My residential geothermal heating and cooling unit wasn't working properly. I retained Comfort Pro's services based on the recommendation of the previous homeowner, and my initial experience in dealing with them was positive. With the purported diagnosis and repair though things quickly went off.
The technician sent by Comfort Pro was very young, and spent much of the time of his two visits on the phone with the manufacturer trying to trouble-shoot the problem. He clearly had no idea what he was doing. In spite of hours in my home, and various manoeuvres including the replacement of several key parts, the repair was not effected. I contacted the office and sent pictures and an explanation. I was told the owner Tom would get back to me.
Three weeks later, I'd still received no reply. Note this was in the summer and the geothermal cooling unit was not functioning this entire time.
With absolutely no confidence in Comfort Pro's ability to fix the issue I contacted the manufacturer and on their recommendation hired a second repair company. That company was quickly able to diagnose and fix the problem. In hindsight the work diagnosed and done by ComfortPro had no bearing on the problem, in fact one key component had been further damaged during their attempted repair.
So the lesson is to contact the manufacturer and get recommendations!